The Circulatory System - Blood

Question 1

What 4 main things does the blood consist of?

Answer 1

Red Blood Cells, White Blood Cells, Platelets, and Plasma

Question 2

What is the function of red blood cells?

Answer 2

They make up half of our blood by volume, and their role is to carry oxygen from the lungs to our body’s tissues so that our cells can use it in cellular respiration.

To do this, they contain a red pigment called haemoglobin, which combine oxygen to become oxy haemoglobin.

Once the RBC have traveled around the body into the tissues, the oxy haemoglobin can split back into haemoglobin and oxygen again, so the oxygen is free to diffuse into our tissues.

Question 3

What are the 2 adaptations of red blood cells?

Answer 3

1. They don’t have a nucleus, which means there is more space for haemoglobin and oxygen.
2. They are shaped like a biconcave disk, which gives them a large surface area for absorbing oxygen.

Question 4

What is the function of white blood cells?

Answer 4

They make up less than 1% of our blood, however they are an essential part of our immune system. They defend against infection.

Question 5

How do white blood cells defend against pathogens?

Answer 5

1. Phagocytosis
   This is when a white blood cell will engulf or consume a microorganism.
2. Producing Antibodies
   These can bind onto pathogens and help destroy them.
3. Producing Antitoxins
   Neutralise any toxins that the pathogens produce

Question 6

True or False?

White blood cells do not have a nucleus.

Answer 6

False

White blood cells DO have a nucleus, however red blood cells do not.

Question 7

Are platelets cells?

Answer 7

No, they are just small fragments of cells. Therefore, they do not have a nucleus.

Question 8

What are the function of platelets?

Answer 8

They float in our blood waiting until we get a cut, and then they rush to the wound and patch up the hole, acting as a glue. We call this process “clotting”. Clotting is important because it stops blood from rushing out, and it also stops microorganisms from getting in, causing infection.

Question 9

What is the function of plasma?

Answer 9

It makes up just over 50% of the blood’s volume, and it is a pale straw coloured liquid. It is what makes the blood watery so it can flow.

It also carries just about everything, including the red blood cells, white blood cells and platelets.
Additionally, it carries nutrients like glucose and amino acids, waste products like carbon dioxide and urea, hormones, proteins, antibodies and antitoxins.

Question 10

How many litres of blood does an adult have in their circulatory system at one time!

Answer 10

5L

Question 11

What are the two types of blood doctors can give out to patients?

Answer 11

Artificial Blood (containing salt water)
- Adds volume to our circulatory system
- Doesn’t contain any red blood cells

Blood Transfusion (real blood that has been donated)
- Has red blood cells